A portable wireless communication device such as a cell phone, personal digital assistant, wireless email device, pager, and the like may be carried by an owner/user on their person. A typical method for carrying such a portable device is for the owner to wear a holster on which the portable device is quick-release connected. The quick-release connection may permit the owner to easily remove the portable device from the holster. A disadvantage of the quick-release connection is that the portable device may come out of the holster through inadvertent contact with an object, or by an unauthorized person removing the portable device. In both cases, this may happen without the knowledge of the owner of the portable device. Such a loss may create numerous problems for the owner of the portable device.
For instance, the owner may have to obtain and pay for a replacement portable device. The owner may have to cancel any services enabled by the portable device, such as phone service, to prevent unauthorized charges to the owner. Additionally, there are potential problems with preventing the disclosure of the information that was stored on the portable device. For instance, portable devices have become indispensable work tools and therefore the portable device may have sensitive business information whose dissemination needs to be controlled.
Consequently, a number of schemes have been developed to address some of these potential problems. For example, U.S. Pat. No. 6,674,358 to Tinsley discloses a holstered portable device that includes a sensor for determining if the portable device has been removed from the holster. If the portable device has been removed from the holster, an alert may be sounded and the alert may be deactivated by the entry of a series of keystrokes on the portable device. Similarly, U.S. Pat. No. 6,836,212 to Sawinski also discloses a system that alerts a user when a portable device is removed from a holster. It further discloses that the portable device may be instructed by the alert program to transmit a stored message over a wireless channel to a user-identified target such as another wireless device carried by the user.
U.S. Pat. No. 5,610,979 to Yu discloses a system that that alerts a user when a portable device is removed from a holster. The holster has a contact interface that mates with a contact interface on the portable device, and when the contact between the two contact interfaces are interrupted, an alert is generated for the user.
U.S. Pat. No. 6,831,567 to Liao also discloses a holster for carrying a portable device. The holster has a receiver tuned to a circuit on the portable device, and when the portable device exceeds a certain distance from the holster, an alert is generated for the user.